package com.sloera.nowcoder;

import java.util.Scanner;
import java.util.regex.Pattern;

/**
 * class com.sloera.nowcoder
 * user sloera
 * date 2022/2/27
 */
public class HJ20 {
    public static void main(String[] args) {
        final Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            final String s = in.nextLine();
            boolean flag = isValid(s);
            if (flag) {
                System.out.println("OK");
            } else {
                System.out.println("NG");
            }
        }
    }

    private static boolean isValid(String s) {
        // 1.长度超过8位
        if (s.length() <= 8) {
            return false;
        }
        // 包括大小写字母.数字.其它符号,以上四种至少三种
        final Pattern lowerAlphabet = Pattern.compile(".*[a-z]+.*");
        final Pattern upperAlphabet = Pattern.compile(".*[A-Z]+.*");
        final Pattern number = Pattern.compile(".*[0-9]+.*");
        final Pattern other = Pattern.compile(".*[^0-9a-zA-Z]+.*");
        int count = 0;
        if (lowerAlphabet.matcher(s).matches()) {
            count++;
        }
        if (upperAlphabet.matcher(s).matches()) {
            count++;
        }
        if (number.matcher(s).matches()) {
            count++;
        }
        if (other.matcher(s).matches()) {
            count++;
        }
        if (count < 3) {
            return false;
        }
        // 不能有长度大于2的不含公共元素的子串重复
        if (Pattern.compile("^.*(.{3,}).*\\1.*$").matcher(s).find()) {
            return false;
        }
        return true;
    }
}
